text: /*
   * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions are met:
   *
   * 1. Redistributions of source code must retain the above copyright notice, this
   *    list of conditions and the following disclaimer.
   *
   * 2. Redistributions in binary form must reproduce the above copyright notice,
   *    this list of conditions and the following disclaimer in the documentation
   *    and/or other materials provided with the distribution.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
   * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
   * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
   * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
   * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
   * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
   * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
   * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  
  #include <AK/NonnullRefPtrVector.h>
  #include <Kernel/Process.h>
  #include <Kernel/VM/InodeVMObject.h>
  #include <Kernel/VM/MemoryManager.h>
  #include <Kernel/VM/PurgeableVMObject.h>
  
  namespace Kernel {
  
  int Process::sys$purge(int mode)
  {
      REQUIRE_NO_PROMISES;
      if (!is_superuser())
          return -EPERM;
      int purged_page_count = 0;
      if (mode & PURGE_ALL_VOLATILE) {
          NonnullRefPtrVector<PurgeableVMObject> vmobjects;
          {
              InterruptDisabler disabler;
              MM.for_each_vmobject([&](auto& vmobject) {
                  if (vmobject.is_purgeable())
                      vmobjects.append(static_cast<PurgeableVMObject&>(vmobject));
                  return IterationDecision::Continue;
              });
          }
          for (auto& vmobject : vmobjects) {
              purged_page_count += vmobject.purge();
          }
      }
      if (mode & PURGE_ALL_CLEAN_INODE) {
          NonnullRefPtrVector<InodeVMObject> vmobjects;
          {
              InterruptDisabler disabler;
              MM.for_each_vmobject([&](auto& vmobject) {
                  if (vmobject.is_inode())
                      vmobjects.append(static_cast<InodeVMObject&>(vmobject));
                  return IterationDecision::Continue;
              });
          }
          for (auto& vmobject : vmobjects) {
              purged_page_count += vmobject.release_all_clean_pages();
          }
      }
      return purged_page_count;
  }
  
  }
  